At present, video live broadcast services on a network are becoming more popular. A user may watch a network live video program using a terminal such as a personal computer, a tablet computer, or a mobile phone. A network live video has a strict requirement on real-time performance, that is, a specific data unit is decoded and displayed within a specific time period, which requires a network to provide enough bandwidth and an ensured time delay and loss rate. However, due to various reasons, network video applications face different requirements of service quality, and the various reasons include: that a growing speed of network resources cannot match a growing speed of video applications, that a network service does not ensure service quality, that a network features heterogeneity, and that users have different requirements. Therefore, for a fixed network or a mobile network, a lack of an ensured time delay and synchronization seriously affects experience of a user in watching live broadcast.
When the prior art is used to perform video live broadcast, user equipment (UE) sends a streaming media request to a streaming server at a T1 moment; and the Streaming server starts to respond to the UE, and sends a first video data packet to the UE at a T2 moment, and after completing sending the first video data packet, the streaming server continues to send a second video data packet, and so on, until sending of video data packets requested by a user is completed. In this case, before playing a video, the UE needs to wait to a T3 moment when video data of enough length has been buffered in a video buffer area. Similarly, after another UE sends a streaming media request, the Streaming server sends video data packets to the UE in a same manner.
However, when different UEs request video live broadcast, transmission delays from the Streaming server to the different UEs are different, and video buffer delays required for the different UEs are different, causing that the different UEs are not synchronous when playing a same live broadcast video, thereby reducing user experience.